Research Information System
8th International Polymer Congress 2023, İstanbul, Turkey, 12 - 14 September 2023, pp.74-75, (Full Text)
For a vast range of biomedical applications, such as tissue engineering and drug delivery, it is important to develop strategies for synthesizing novel nanocomposites for inclusion in biofilms. Specifically, in the context of tissue engineering, it becomes crucial to create a biocompatible and bioactive matrix capable of enhancing the biological characteristics of the substrate, thereby promoting cell adhesion and proliferation. This study aims to enhance the properties of chitosan, making it more efficacious for biological applications and better suited to human physiology. This is achieved through the blending of a natural polymer, a 0.2% chitosan solution dissolved in acetic acid, with polyethylene glycol (PEG4000) in a 1:1 ratio (v/v). The crosslinking of chitosan/PEG4000 is achieved using glutaraldehyde. Furthermore, given that several studies have demonstrated that clay-chitosan composites can augment the mechanical strength of films, our objective is to investigate whether the addition of 0.1% smectite clay to chitosan/PEG4000 composites can also heighten the bioactivity of the film. This study seeks to determine if such blending provides an optimal environment for cell growth and adhesion on the film's surface. In this study, two groups of samples named S4 and S5 were prepared. Both samples were obtained by mixing chitosan (a natural polymer in 0.2 % w acetic acid solution) and polyethylene glycol (PEG4000). Glutaraldehyde was used as a crosslinker. Smectite clay (0.1% w/v) was added to one of the samples to investigate its effect on cell growth. The films were tested in a cell culture medium beforehand, to analyze whether their reaction with the growth medium would cause any pH change which might not be suitable for cell viability. The films were sterilized by exposing the UV light on both sides for 15 min before being used in the cell culture. Subsequently, the sterilized films were placed in a 96-well plate and washed with 1X phosphate-buffered saline (PBS) solutions. The next day, 5,000 mouse fibroblast (L929) cells were seeded onto films in each well of a 96-well plate. The plate was incubated for 24-72h in a 5% CO2-containing humidified incubator at 37o C. Non-cell-seeded versions of each polymer were also used as blank. At the end of each incubation time point, 0.5 mg/ml cell viability solution (MTT) was applied to the polymers, and cell viability of the cells on the films was evaluated using a spectrophotometer at 570 nm. The cell viability assay, conducted using MTT, indicated that both S4 and S5 exhibited enhanced cell viability on the film matrix after 24-72 hours of incubation. However, during the 48-hour incubation period, the cell viability on the S4 polymer, which does not contain smectite clay in its structure, showed a slightly higher cell viability compared to S5. Additionally, a marginal decrease in cell viability was observed in both polymers after the 72-hour incubation period. These results suggest that both S4 and S5 polymers are biocompatible and conducive to cell growth. The minor increase in cell viability observed in S4 at the 48-hour mark, relative to S5, may indicate that the addition of smectite clay has a limited impact on cell growth. Overall, our study reveals that both 0.1% smectite clay-containing (S5) and non-containing (S4) chitosan/PEG4000 nanocomposite films exhibit promising potential for biomedical studies requiring and working with living cells. Nevertheless, further research is warranted to validate these findings and explore the potential advantages associated with the incorporation of smectite clay into the polymer matrix.
Keywords: chitosan/PEG4000 nanocomposites, cell viability, smectite clay
igure 2. Adhesion and growth of L929 cell line on A) S4 and B) S5 films were observed under the phase contrast microscope. The representative images of viable L929 cells on the films were taken after 72h of incubation. (Red arrows: adherent viable cells on the film matrix). Scale bar 100 μm (at 40X magnification).
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